1. Field of the Invention
The invention generally pertains to oil wells and more specifically to a system for servicing oil wells.
2. Description of Related Art
After a well is set up and operating to draw petroleum, water or other fluid up from within the ground, various service operations are periodically performed to maintain the well. Such service operations may include replacing worn parts such as a pump, sucker rods, inner tubing, and packer glands; pumping chemical treatments or hot oil down into the well bore; and pouring cement into the well bore to partially close off a portion of the well (or to shut it down entirely). Since wells are often miles apart from each other, the maintenance or service operations are usually performed by a mobile unit or service vehicle having special onboard servicing equipment suited to perform the work. Some examples of service vehicles include a chemical tank truck or trailer, a cement truck or trailer, a hot-oiler tank truck or trailer, and a portable work-over service rig having a hoist to remove and install well components (e.g., sucker rods, tubing, etc.).
Service vehicles are often owned by a contractor that the well owner hires to service the wells. Typically, the contractor performs the work and invoices the owner. For many service operations, it is difficult for the owner to confirm exactly what work was actually done or how well it was done, without actually witnessing the work while it is in progress. In the case of pumping a chemical treatment down into a well bore, it is virtually impossible to confirm how much chemical was dispensed after the fact. Other examples would include not being able to confirm the temperature or quantity of a hot oil treatment, the quantity and position of replaced sucker rods or tubing, and the torque used in tightening sucker rods or tubing. There are numerous other possible service operations that are difficult to confirm after the work has been reported as having been completed. Unfortunately it is impractical the well owner to travel to the various remote well sites, arrive at the right moment, and wait around until the work is complete. Consequently, the well owner often relies on the integrity of the contractor. However, even the most reputable contractor (e.g., Fred Newman of Midland, Tex.) can make an honest mistake, as it can be difficult to accurately keep a myriad of process data readings in order and correctly associated with the right oil well, especially when they look so similar.
To avoid the problems and limitations of existing well servicing systems, it is an object of the invention to provide a well servicing system that reliably monitors the performance of a well servicing operation, properly associates the operation to the correct well, and secures the combined results to protect against unauthorized changes or tampering of data.
A second object is to provide a secure record that can be relied upon at a later date to resolve a maintenance problem, resolve a question of theft, or determine the cause of an accident that may have occurred at the well site.
A third object is to provide a well servicing system for use on a mobile well servicing vehicle.
A fourth object is to provide a durable well identification device that stores a digital well identification value without having to maintain the device with a source of electrical power.
A fifth object is to provide a well servicing system that minimizes a temptation for others to improperly alter data.
A sixth object is to provide a well servicing system that lends itself well to a wide variety of processes.
A seventh object is to eliminate much of the paper shuffling that is often associated with an invoice created by several people manually comparing handwritten work reports to purchase orders, contracts, and a myriad of other documents.
These and other objects of the invention are provided by a novel well servicing system that includes a mobile transducer that senses a parameter of a service operation performed at a plurality of well sites, and includes a memory that stores information provided by the transducer with reference to a well site identifier at each well site to associate the information with the proper well site at which the service operation was performed.